Stadium Ventilation BM418/B - "Black Hole Vario" Core Drill Ventilator complete with Brown Air Blast Cowl to fit walls up to 350mm thick.Core Drill Ventilators are designed for use when ventilating a gas appliance, but can also be used for general through wall ventilation. They can easily be fitted in both refurbishment and new build situations with the use of a Ø 5" (127mm) diameter core drill. For situations where the total wall thickness exceeds 350mm, a 1,000mm Extension Tube can be purchased separately - Stadium Ventilation BM810 .Benefits of the "Black Hole" range:Stops wind blasting in - The air flow within the duct is slowed down by the change of direction and by the vortices formed, reducing draughts to a minimum. Stops light showing through - The occupier cannot see through the ventilator and is less likely to be worried that insects and vermin may enter the house through it. Stops light shining out - Night flying insects like moths, craneflies, and mosquitoes are not attracted in. Absorbs outside noise - Reduces the penetration of traffic noise. The internal construction works as a sound baffle. Allows air to be pulled through by the appliance when it is operating. Safety - With draught and light annoyance problems eliminated, the occupier will not be tempted to block off the vent.

"Black Hole" ventilation products provide the answer to the dangerous practice of ventilators being blocked off by occupiers who are being annoyed by draughts. This makes an important contribution to safety. New tests show that while this works the ventilator may not pass the required amount of air when the appliance is operating. THEREFORE IT IS IMPORTANT THAT A SPILLAGE TEST IS CARRIED OUT AS REQUIRED BY THE BRITISH STANDARD.Core Drill "Black Hole Vario" Ventilator BM418/B features:BM418/B Ventilator includes: Cavity liner - black plastic tube, standard length: 350mm (14''), diameter: Ø 127mm (5“); Air blast exterior cowl - brown plastic; Inner grille - white plastic; Anti-draught baffle supplied, reduces the ‘Effective Free Area'.Effective free area: 100cm² - without anti-draught baffle, 70cm² - with anti-draught baffle. For use with open flued appliances with an input rating up to: 27kW (92,000 Btu/h) - without anti-draught baffle, 21kW (71,500 Btu/h) - with anti-draught baffle. Complies with BS 5440 Part 2, 2000.For more information, please visit this products specification webpage .